This is the third and final inspection campaign this year from Employment and Immigration Minister Thomas Lukaszuk, who earlier targeted workplaces that employ young people and workplaces that use forklifts.

"We put the industry on notice. We let them know that we perceive them to be problematic," Lukaszuk said.

But critics question the timing of Lukaszuk's announcement, saying he shouldn't have warned employers ahead of time.

"They'll keep their noses clean for the next month or two and then go back to business as usual," said Gil McGowan, president of the Alberta Federation of Labour. "And business as usual means that an unacceptably high number of construction workers will continue to be put at risk."

Last year, Occupational Health and Safety officers conducted nearly 1,700 inspections in the residential construction sector and issued 1,000 orders. The most common infraction was a lack of proper fall protection, which can include guardrails or harnesses, followed by issues with hazard assessments, safeguards and clear entrances, walkways and stairways.

Bob Barnetson, a professor of labour relations at Athabasca University, said the numbers suggest a pervasive problem.

"If more than half of employers aren't complying in a very small number of inspections, I think that's good evidence of widespread non-compliance," he said, adding that there is no financial incentive for employers to ensure worker safety and little disincentive if they don't.

"There's not very much chance of them getting caught violating the law. And if they do get caught, there's basically no chance there's going to be any sort of penalty."

McGowan attributed the "abysmal" condition of residential construction sites to a hot economy, which has increased demand for housing while at the same time drawing experienced workers to the more lucrative commercial and industrial construction industry. He said if the province really wanted to improve conditions, it would conduct inspections more frequently and without warning.

Lukaszuk shot down the criticisms, saying "the warning is always out."

"You should not be safe because I'm sending officers out to catch you. You should be safe because you want to come home at the end of the night to your family and you don't want your workers to get hurt," he said.

Lukaszuk also announced Monday that he has ordered a draft of legislation that would allow occupational health and safety officers to ticket workers and fine employers on the spot. He also said a smartphone app is in development that would let anyone anonymously submit a photo and location of a safety violation. He also dismissed McGowan's call for whistleblower legislation that would protect the identities of employees who report violations at their workplaces.

"If everyone can report on anyone anonymously and all complaints are looked into, I don't know what is left out," Lukaszuk said.

Barnetson said the government's real test will be what action it takes after the blitz is over.

"Charitably, this is a warning to the industry to do something. Uncharitably, this is a PR stunt by the government," he said.

The Alberta chapter of the Canadian Home Builders' Association, which represents the province's residential construction industry, did not respond to request for comment Monday.